title: Hyperthermia increases natural killer cell cytotoxicity against SW-872 liposarcoma cell line.
abstract: BACKGROUND
  Although there is convincing data in support of the effectiveness of hyperthermia in tumor therapy, the molecular mechanisms underlying the clinical effects of hyperthermia are still poorly understood.
  
  
  OBJECTIVE
  To investigate natural killer (NK) cell cytotoxicity against heat-treated SW-872 and HeLa tumor cell lines.
  
  
  METHODS
  NKG2D ligands and HLA class I transcription were examined using quantitative real-time PCR in treated tumor cell lines at 0, 2, 4, 6 and 12 h following thermal treatment at 39C and 42C for 1 h. The expression of MICA/B, ULBP1 and ULBP2 were also determined by flow cytometry. NK92-MI cytotoxic activity against heat-treated target cell lines was assessed by LDH release as well as annexin-V and 7-AAD assays.
  
  
  RESULTS
  Our results showed that heat treatment at 39C improved the cytolytic activity of NK cells against SW-872 cells without increasing NKG2D ligand concentration or decreasing HLA class I levels.
  
  
  CONCLUSIONS
  The observed increase in the cytotoxicity of NK cells against SW-872 cells after hyperthermia does not coincide with changes in MICA/B, ULBP1 and ULBP2 ligands of NKG2, however, the expression of other ligands in target cells may have made the cells susceptible to the cytotoxic effect of NK cells.
authors.affiliation: Department of Immunology, Shiraz University of Medical Sciences, Shiraz, Iran, e-mail: farjadsh@sums.ac.ir.
authors.forename: Shirin
authors.initials: S
authors.lastname: Farjadian
authors.forename: Marzie
authors.initials: M
authors.lastname: Norouzian
authors.forename: Vahid
authors.initials: V
authors.lastname: Younesi
authors.forename: Azin
authors.initials: A
authors.lastname: Ebrahimpour
authors.forename: Ramin
authors.initials: R
authors.lastname: Lotfi
mesh_terms: D003602:Cytotoxicity, Immunologic; D058851:GPI-Linked Proteins / Q000378:metabolism; D006680:HLA Antigens / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006358:Hot Temperature / Q000627:therapeutic use*; D006801:Humans; D006979:Hyperthermia, Induced; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D007694:Killer Cells, Natural / Q000276:immunology*; D055655:NK Cell Lectin-Like Receptor Subfamily K / Q000235:genetics / Q000378:metabolism; D009369:Neoplasms / Q000628:therapy*
chemical_list: D058851:GPI-Linked Proteins; D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I; D036341:Intercellular Signaling Peptides and Proteins; D047908:Intracellular Signaling Peptides and Proteins; C527085:KLRK1 protein, human; C099187:MHC class I-related chain A; D055655:NK Cell Lectin-Like Receptor Subfamily K; C423231:ULBP1 protein, human; C423230:ULBP2 protein, human